Hostilities are rapidly escalating among the trio of candidates, who have lobbed verbal grenades at each other over support for legalizing marijuana, unsubstantiated racism claims and their qualifications for the state's second highest office.

"I think it's very likely that there's going to be warfare east of the Connecticut River," Walker, 62, said, referring to Bacchiochi and Somers. "I'm going to try to stay above the fray and run a positive, fact-based and solutions-oriented campaign based on my ability, my integrity and my proven record of producing results."

But since the eve of the state Republican convention in May at Mohegan Sun, the name-calling and vitriol have only increased.

Bacchiochi's work as a paid lobbyist for the Marijuana Policy Project, which paid her $113,000 to promote the legalization of medical marijuana outside Connecticut, is drawing criticism from both of her opponents.

"For me, it's not what she was lobbying for," Somers said. "It's the fact that she was being paid out of state for the same thing that she was lobbying for here in Connecticut. Although it might not be illegal, it definitely pushes the ethics boundary."

Bacchiochi, 53, declined to be interviewed. Her campaign issued a statement to Hearst Connecticut Media.

"As the endorsed Republican candidate for lieutenant governor, I am concerned only about issues that matter: helping our middle class, jobs, fiscal sanity and a government that responds to the needs of those truly in need," the statement read. "Anything else is a distraction and waste of our precious time."

The GOP primary victor will be paired with either Foley or McKinney, who is Walker's running mate. Bacchiocchi and Somers are running on their own, with Somers having broken an alliance with Boughton before he dropped out of the race for governor.

The primary winners will face Gov. Dannel P. Malloy and Lt. Gov. Nancy Wyman, a popular Democrat who previously served as state comptroller and helped spearhead Connecticut's rollout of its health care exchange under the Affordable Care Act.

While the Republican field for governor has contracted, the competition for the GOP nomination for lieutenant governor has turned into a grudge match.

"I told her I better not hear that again," Walker said, characterizing the label as false and defamatory.

Somers, 48, stood by her remarks, saying her background, starting a medical-device company in the private sector and serving as Groton mayor from late 2011 through 2013, is a better fit for the job of lieutenant governor.

"I don't know why someone who has spent 35 years in Washington would be offended by that," Somers said.

Besides, Somers said, Walker has taken to belittling her service as Groton mayor.

"He likes to call me a ceremonial mayor," Somers said.

Groton has a town manager and a nine-member Town Council, which chooses a mayor from its ranks. Somers continues to serve on the council.

During a radio talk show appearance Monday, Bacchiochi tried to distance herself from allegations -- attributed to her by multiple media outlets in May -- that Walker's campaign told GOP delegates not to support her because she is married to a black man.

Bacchiochi blamed the media for a misunderstanding, saying she would never accuse someone without the facts.

"It's a typical attempt by a politician to distort the facts to deceive the people," Walker said. "She's trying to re-create history."

State GOP Chairman Jerry Labriola Jr. downplayed the strife among the candidates, saying each would make an excellent lieutenant governor.

"Although they are competing now, they are united in their commitment to fix Connecticut's economy," Labriola said.

Some say the ferocity of the campaign belies the historically deferential role played by the lieutenant governor, who presides over the state Senate and has tie-breaking powers.

"We have saying in academic circles: The battles are so acrimonious because the stakes are so small," said Scott McLean, a political science professor at Quinnipiac University in Hamden. "I think it translates to some extent to the lieutenant governor's race."

Both Walker and Somers said they wouldn't be running if that was the case.

"Three of the past seven lieutenant governors have become governor," Walker said. "So it is very possible that next lieutenant governor could become governor."